In order to prevent malware from replacing critical system components with compromised copies, Windows works very hard to maintain the integrity of the system files on your machine. If you try to replace one of the “protected” files, you may get a message that the operating system has put the old approved version back. That’s “Windows File Protection”, now called “Windows Resource Protection”.
Unfortunately, there are occasional ways around system file protection. Sometimes it’s as simple as a hard disk error causing a system file to be damaged and become corrupt.
As a result, automated checking is nice, but sometimes you need to take matters into your own hands.
Enter the SFC, the System File Checker.